Running Calculator with adjustments for temperature and body weight, plus FIRST training paces

This calculator will generate training paces, race prediction, with adjustments for temperature, body weight and altitude. This calculator works by estimating your V̇O2max and using that to predict your race times and training paces. To find out your V̇O2max and associated paces, you will need the results of a recent race into the form below.

You may have several race results that indicate different V̇O2max values. If the races are all reasonably recent and reflect your current fitness level, use the best. If you've been injured or had a break from training since your last race, you should not use an old race result.

This Calculator will also attempt to compensate for races run in hot conditions. This is based on the research documented at Impact of Heat on Marathon Performance and is an estimate only. If you enter your weight, the calculator will predict your race performances at different body weights, assuming the weight change is due to body fat only.

This calculator no longer generates VDOT paces nor will it output the long runs for the Jack Daniels marathon plans. Jack Daniels requested the removal of this functionality.